<?php
/**
 * Zend Framework
 *
 * LICENSE
 *
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 *
 * @category   Zend
 * @package    Zend_Cache
 * @subpackage Zend_Cache_Frontend
 * @copyright  Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 * @version    $Id: Page.php 18951 2009-11-12 16:26:19Z alexander $
 */


/**
 * @see Zend_Cache_Core
 */
require_once 'Zend/Cache/Core.php';


/**
 * @package    Zend_Cache
 * @subpackage Zend_Cache_Frontend
 * @copyright  Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */
class Zend_Cache_Frontend_Page extends Zend_Cache_Core
{
	/**
	 * This frontend specific options
	 *
	 * ====> (boolean) http_conditional :
	 * - if true, http conditional mode is on
	 * WARNING : http_conditional OPTION IS NOT IMPLEMENTED FOR THE MOMENT (TODO)
	 *
	 * ====> (boolean) debug_header :
	 * - if true, a debug text is added before each cached pages
	 *
	 * ====> (boolean) content_type_memorization :
	 * - deprecated => use memorize_headers instead
	 * - if the Content-Type header is sent after the cache was started, the
	 *   corresponding value can be memorized and replayed when the cache is hit
	 *   (if false (default), the frontend doesn't take care of Content-Type header)
	 *
	 * ====> (array) memorize_headers :
	 * - an array of strings corresponding to some HTTP headers name. Listed headers
	 *   will be stored with cache datas and "replayed" when the cache is hit
	 *
	 * ====> (array) default_options :
	 * - an associative array of default options :
	 *     - (boolean) cache : cache is on by default if true
	 *     - (boolean) cacheWithXXXVariables  (XXXX = 'Get', 'Post', 'Session', 'Files' or 'Cookie') :
	 *       if true,  cache is still on even if there are some variables in this superglobal array
	 *       if false, cache is off if there are some variables in this superglobal array
	 *     - (boolean) makeIdWithXXXVariables (XXXX = 'Get', 'Post', 'Session', 'Files' or 'Cookie') :
	 *       if true, we have to use the content of this superglobal array to make a cache id
	 *       if false, the cache id won't be dependent of the content of this superglobal array
	 *     - (int) specific_lifetime : cache specific lifetime
	 *                                (false => global lifetime is used, null => infinite lifetime,
	 *                                 integer => this lifetime is used), this "lifetime" is probably only
	 *                                usefull when used with "regexps" array
	 *     - (array) tags : array of tags (strings)
	 *     - (int) priority : integer between 0 (very low priority) and 10 (maximum priority) used by
	 *                        some particular backends
	 *
	 * ====> (array) regexps :
	 * - an associative array to set options only for some REQUEST_URI
	 * - keys are (pcre) regexps
	 * - values are associative array with specific options to set if the regexp matchs on $_SERVER['REQUEST_URI']
	 *   (see default_options for the list of available options)
	 * - if several regexps match the $_SERVER['REQUEST_URI'], only the last one will be used
	 *
	 * @var array options
	 */
	protected $_specificOptions = array(
        'http_conditional' => false,
        'debug_header' => false,
        'content_type_memorization' => false,
        'memorize_headers' => array(),
        'default_options' => array(
            'cache_with_get_variables' => false,
            'cache_with_post_variables' => false,
            'cache_with_session_variables' => false,
            'cache_with_files_variables' => false,
            'cache_with_cookie_variables' => false,
            'make_id_with_get_variables' => true,
            'make_id_with_post_variables' => true,
            'make_id_with_session_variables' => true,
            'make_id_with_files_variables' => true,
            'make_id_with_cookie_variables' => true,
            'cache' => true,
            'specific_lifetime' => false,
            'tags' => array(),
            'priority' => null
	),
        'regexps' => array()
	);

	/**
	 * Internal array to store some options
	 *
	 * @var array associative array of options
	 */
	protected $_activeOptions = array();

	/**
	 * If true, the page won't be cached
	 *
	 * @var boolean
	 */
	protected $_cancel = false;

	/**
	 * Constructor
	 *
	 * @param  array   $options                Associative array of options
	 * @param  boolean $doNotTestCacheValidity If set to true, the cache validity won't be tested
	 * @throws Zend_Cache_Exception
	 * @return void
	 */
	public function __construct(array $options = array())
	{
		while (list($name, $value) = each($options)) {
			$name = strtolower($name);
			switch ($name) {
				case 'regexps':
					$this->_setRegexps($value);
					break;
				case 'default_options':
					$this->_setDefaultOptions($value);
					break;
				case 'content_type_memorization':
					$this->_setContentTypeMemorization($value);
					break;
				default:
					$this->setOption($name, $value);
			}
		}
		if (isset($this->_specificOptions['http_conditional'])) {
			if ($this->_specificOptions['http_conditional']) {
				Zend_Cache::throwException('http_conditional is not implemented for the moment !');
			}
		}
		$this->setOption('automatic_serialization', true);
	}

	/**
	 * Specific setter for the 'default_options' option (with some additional tests)
	 *
	 * @param  array $options Associative array
	 * @throws Zend_Cache_Exception
	 * @return void
	 */
	protected function _setDefaultOptions($options)
	{
		if (!is_array($options)) {
			Zend_Cache::throwException('default_options must be an array !');
		}
		foreach ($options as $key=>$value) {
			if (!is_string($key)) {
				Zend_Cache::throwException("invalid option [$key] !");
			}
			$key = strtolower($key);
			if (isset($this->_specificOptions['default_options'][$key])) {
				$this->_specificOptions['default_options'][$key] = $value;
			}
		}
	}

	/**
	 * Set the deprecated contentTypeMemorization option
	 *
	 * @param boolean $value value
	 * @return void
	 * @deprecated
	 */
	protected function _setContentTypeMemorization($value)
	{
		$found = null;
		foreach ($this->_specificOptions['memorize_headers'] as $key => $value) {
			if (strtolower($value) == 'content-type') {
				$found = $key;
			}
		}
		if ($value) {
			if (!$found) {
				$this->_specificOptions['memorize_headers'][] = 'Content-Type';
			}
		} else {
			if ($found) {
				unset($this->_specificOptions['memorize_headers'][$found]);
			}
		}
	}

	/**
	 * Specific setter for the 'regexps' option (with some additional tests)
	 *
	 * @param  array $options Associative array
	 * @throws Zend_Cache_Exception
	 * @return void
	 */
	protected function _setRegexps($regexps)
	{
		if (!is_array($regexps)) {
			Zend_Cache::throwException('regexps option must be an array !');
		}
		foreach ($regexps as $regexp=>$conf) {
			if (!is_array($conf)) {
				Zend_Cache::throwException('regexps option must be an array of arrays !');
			}
			$validKeys = array_keys($this->_specificOptions['default_options']);
			foreach ($conf as $key=>$value) {
				if (!is_string($key)) {
					Zend_Cache::throwException("unknown option [$key] !");
				}
				$key = strtolower($key);
				if (!in_array($key, $validKeys)) {
					unset($regexps[$regexp][$key]);
				}
			}
		}
		$this->setOption('regexps', $regexps);
	}

	/**
	 * Start the cache
	 *
	 * @param  string  $id       (optional) A cache id (if you set a value here, maybe you have to use Output frontend instead)
	 * @param  boolean $doNotDie For unit testing only !
	 * @return boolean True if the cache is hit (false else)
	 */
	public function start($id = false, $doNotDie = false)
	{
		$this->_cancel = false;
		$lastMatchingRegexp = null;
		foreach ($this->_specificOptions['regexps'] as $regexp => $conf) {
			if (preg_match("`$regexp`", $_SERVER['REQUEST_URI'])) {
				$lastMatchingRegexp = $regexp;
			}
		}
		$this->_activeOptions = $this->_specificOptions['default_options'];
		if ($lastMatchingRegexp !== null) {
			$conf = $this->_specificOptions['regexps'][$lastMatchingRegexp];
			foreach ($conf as $key=>$value) {
				$this->_activeOptions[$key] = $value;
			}
		}
		if (!($this->_activeOptions['cache'])) {
			return false;
		}
		if (!$id) {
			$id = $this->_makeId();
			if (!$id) {
				return false;
			}
		}
		$array = $this->load($id);
		if ($array !== false) {
			$data = $array['data'];
			$headers = $array['headers'];
			if (!headers_sent()) {
				foreach ($headers as $key=>$headerCouple) {
					$name = $headerCouple[0];
					$value = $headerCouple[1];
					header("$name: $value");
				}
			}
			if ($this->_specificOptions['debug_header']) {
				echo 'DEBUG HEADER : This is a cached page !';
			}
			echo $data;
			if ($doNotDie) {
				return true;
			}
			die();
		}
		ob_start(array($this, '_flush'));
		ob_implicit_flush(false);
		return false;
	}

	/**
	 * Cancel the current caching process
	 */
	public function cancel()
	{
		$this->_cancel = true;
	}

	/**
	 * callback for output buffering
	 * (shouldn't really be called manually)
	 *
	 * @param  string $data Buffered output
	 * @return string Data to send to browser
	 */
	public function _flush($data)
	{
		if ($this->_cancel) {
			return $data;
		}
		$contentType = null;
		$storedHeaders = array();
		$headersList = headers_list();
		foreach($this->_specificOptions['memorize_headers'] as $key=>$headerName) {
			foreach ($headersList as $headerSent) {
				$tmp = explode(':', $headerSent);
				$headerSentName = trim(array_shift($tmp));
				if (strtolower($headerName) == strtolower($headerSentName)) {
					$headerSentValue = trim(implode(':', $tmp));
					$storedHeaders[] = array($headerSentName, $headerSentValue);
				}
			}
		}
		$array = array(
            'data' => $data,
            'headers' => $storedHeaders
		);
		$this->save($array, null, $this->_activeOptions['tags'], $this->_activeOptions['specific_lifetime'], $this->_activeOptions['priority']);
		return $data;
	}

	/**
	 * Make an id depending on REQUEST_URI and superglobal arrays (depending on options)
	 *
	 * @return mixed|false a cache id (string), false if the cache should have not to be used
	 */
	protected function _makeId()
	{
		$tmp = $_SERVER['REQUEST_URI'];
		$array = explode('?', $tmp, 2);
		$tmp = $array[0];
		foreach (array('Get', 'Post', 'Session', 'Files', 'Cookie') as $arrayName) {
			$tmp2 = $this->_makePartialId($arrayName, $this->_activeOptions['cache_with_' . strtolower($arrayName) . '_variables'], $this->_activeOptions['make_id_with_' . strtolower($arrayName) . '_variables']);
			if ($tmp2===false) {
				return false;
			}
			$tmp = $tmp . $tmp2;
		}
		return md5($tmp);
	}

	/**
	 * Make a partial id depending on options
	 *
	 * @param  string $arrayName Superglobal array name
	 * @param  bool   $bool1     If true, cache is still on even if there are some variables in the superglobal array
	 * @param  bool   $bool2     If true, we have to use the content of the superglobal array to make a partial id
	 * @return mixed|false Partial id (string) or false if the cache should have not to be used
	 */
	protected function _makePartialId($arrayName, $bool1, $bool2)
	{
		switch ($arrayName) {
			case 'Get':
				$var = $_GET;
				break;
			case 'Post':
				$var = $_POST;
				break;
			case 'Session':
				if (isset($_SESSION)) {
					$var = $_SESSION;
				} else {
					$var = null;
				}
				break;
			case 'Cookie':
				if (isset($_COOKIE)) {
					$var = $_COOKIE;
				} else {
					$var = null;
				}
				break;
			case 'Files':
				$var = $_FILES;
				break;
			default:
				return false;
		}
		if ($bool1) {
			if ($bool2) {
				return serialize($var);
			}
			return '';
		}
		if (count($var) > 0) {
			return false;
		}
		return '';
	}

}
